I recently posted ongoing problems with my '95 850 sedan. A number of people suggested the throttle position sensor was to blame. I installed the new one last night and low and behold the car drives and shifts perfectly.....Thanks to everyone.........

My car started having an abrupt shift between 4th & 5th gears about 6-8K miles ago. Then about 3K miles ago, it started trying to hunt between gears after leaving from a stop. It would always engage right away after depressing the gas pedal. It gave codes for the speed sensor as well as the PRNDL (gear selector switch) These were replaced and only briefly curing the problem. No codes ever came up for the throttle position sensor. Also, while crusing at freeway speeds 70 plus, it would want to down shift like I was passing someone.
Someone on the VolvoSpeed site suggested the TPS. My local Volvo dealer (here in north Florida) wanted $105 for it, but I go through a Volvo in Brentwood, MO. They wanted $66 plus $8 shipping. Call 1-800-844-9502 and ask for Richard in parts, tell him Bob Baker in Florida recommended you. He has helped me out so many times in the past for all my Volvo cars that I have.

I hope this helps everyone......Good luck.

Can you describe the symptoms you were experiencing before you replaced the TPS?

Oftentimes transmission problems are attributable to the PNP switch going bad.

Apparently, you had another problem.

I'd like to know because I have a 10 year old 850 and like to anticipate what issues I may face to maintan it.

I have a problem with shifting from stop after driving for awhile. When I press the gas padel my car stays still for awhile as if it's in neutral and then kick in to gear. Did it happen to your? How much is the TPS? Where did you get it?
Thanks

My '95 does this also. Seems to be heat related. It usually only happens after going a few higher speed freeway miles or after downshifting going up a long hill. Starts out really slow like in "winter mode" then abruptly shifts into first and proceeds to upshift normally. I can feel when this is about to happen by the hard/sticky downshifts that occur when coming to a stop. Sometimes standing on the brake and giving it some gas will force the stuck device, whatever it is, to "unstick" itself and it then starts properly. Not running the ac seems to help and I've also added an external Hayden trans cooler. Make sure the fluid isn't burned as this will agrevate the problem. Mine's been like this for a couple of years and the car has 98k miles. I suspect the transmission spent some hard time in the "sport" mode at the hands of the previous owners teenage son. Although I've seen a few other postings like this and they all seem to involve the '95 model year.

I also have external trans cooler. Still the same problem. I had flushed ATF many times and now with Mobil 1 synthetic ATF. Doesn't make much difference. Now I order cooling fan to cool the external cooler. I'll find out after installing the fan. I notice though, with the AC on the problem seems to go away since the radiator cooling fan is on as soon as AC is on. Probably the fan cools external cooler. I installed the external cooler infront of AC condenser and radiator.

I think not having the ac on helps because with it's off there's no heat coming from the condenser in front of the radiator. This extra heat only adds to the allready hot transmission fluid in the normal cooler that is part of the radiator. I have to change my fluid every 8-10 k miles because it gets burned. There's something slipping in the tranny and it's just a matter of time before the whole thing will need replacement. Good luck w/ yours.......